DEKALB — The Mid-American Conference West lead was supposed to be decided by stopping the big play.

Both coaches said so.

Ball State turned that theory into a lie for 55 minutes by picking Northern Illinois apart with a relentless bunch of medium-sized gains and nullifying the effect of NIU’s two biggest plays. But the Huskies found a way to keep their BCS hopes alive with two late big plays in Wednesday’s 48-27 victory on ESPN2.

Ball State (9-2, 6-1 MAC West) never had a gain longer than 21 yards, but put together three consecutive TD drives in the first half to take a 21-13 lead. And when NIU scored on a one-play drive on a 58-yard catch-and-run by Da’Ron Brown, it came so quick that the Cardinals still had 73 seconds left in the half to tack on a field goal for a 24-20 lead.

And when Brown caught a 54-yard bomb in the fourth quarter, he fumbled at the end of the play, giving Ball State the ball at its own 13 with the score tied at 27.

NIU, ranked No. 15 in the BCS standings, converted a pair of fourth-and-1 plays and scored on a 16-play, 85-yard drive on its first possession of the second half to lead 27-24. George Rainey then held Ball State to a tying field goal by stuffing the Cardinals on third-and-goal from the 1.

Brown (209 yards) redeemed himself with a 36-yard TD catch to put NIU ahead 34-27 with 5:49 left. Lynch kept that 94-yard drive alive by somehow avoiding a sack and throwing a 25-yard strike to Matt Williams on third-and-11. He also scrambled for a first down on another such play earlier.

“We had them in third-and-long a bunch and didn’t get them off the field enough,” Ball State coach Pete Lembo said. “It was a great play by Jordan breaking free and scampering for the first down. That was a critical one.”

NIU (10-0, 6-0) can wrap up its fourth straight MAC West title with a win Wednesday at Toledo (7-3, 5-1).

NIU, down to its fourth-and fifth-string running backs for most of the game, won this game with passing. Lynch was 25-for-31 for 337 yards. Lynch also ran for 123 yards and two TDs, including a 16-yard insurance TD with 1:26 left. Joe Windsor tacked on another score with a 49-yard interception return in the last minute.

Keith Wenning, the MAC’s leading passer, threw for 324 yards for Ball State, but NIU held the Cardinals to three points in the second half.

“Give Northern’s defense credit,” Wenning said. “We just couldn/t keep the drives going. We’d move the ball. We’d have a long drive, get on their side of the field and the drive would just kind of stall.”